1. Field of the Invention
The present invention relates to a method for the manufacture of formed products, of plate-like or three-dimensional shapes which possesses a density at or near the theoretical value and have a desired thickness and more particularly to a method for the manufacture of such formed products from non-equilibrium and/or metastable metallic or non-metallic powders, foils, or fine wires, for example, produced by rapid quenching or mechanical alloying method.
2. Description of the Prior Art
Non-equilibrium and/or metastable materials possess superior physical and chemical properties. However, since they are produced by forced cooling techniques, they are in the form of powders, foils or fine wires, and are thus restricted as regards fields of utilization.
In the conventional powder rolling process it is hard to obtain effective biting of the powder by the rolling rolls because the powder is under no restriction whatsoever during the feeding thereof. Accordingly, it is not possible to produce a thick formed product and uniform rolling is also difficult. In addition, a low green density is unavoidable because heavy rolling reduction is impossible.
Various methods for rolling a container filled with powder have been disclosed as follows: Japanese published examined patent application Nos. Sho-55-1323, Sho-57-41521 and Sho-60-58289 and published unexamined patent application No. Sho-56-45289. These relate to methods wherein a powder is charged into a metal container, is optionally powder sintered, the container and powder are then heated to a high temperature at which the powder is easily sintered and the resistance of the container to deformation is small, and the container and the powder are then subjected to hot rolling to obtain a formed product.
These methods are advantageous in that the container need not have high strength and that a formed product can be obtained efficiently.
However, these known methods which involve heating of the powder to a high temperature are not appropriate for manufacturing solid shaped products from non-equilibrium and/or metastable materials because the excellent physical and chemical properties of these materials are lost by heating to a high temperature.